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Environmental contamination from mixtures of chemical substances and materials resulting from anthropogenic activities has adverse effects on aquatic biota. Fipronil (FP) is an insecticide widely used in agriculture and public health and is frequently detected in environmental compartments. Microplastics (MPs) represent another class of contaminants that have raised concerns due to their ability to adsorb pollutants, potentially acting as a vector. This study evaluated the influence of polyethylene microplastics on the toxicity of FP in zebrafish (Danio rerio) embryos/larvae. Zebrafish embryos were exposed to aqueous suspension containing purified FP and the FP + MP mixtures for 120 h. Mortality, teratogenicity and cardiotoxicity were observed during the zebrafish development. Larvae were more sensitive to FP than the embryo. The presence of MPs reduced lethality; however, no significant changes were observed for sublethal endpoints. Our findings demonstrate the acute impact of FP on zebrafish embryos/larvae, demonstrating that MPs interfere with toxicity. Therefore, understanding the mechanisms of interaction between contaminants of different classes is essential for predicting the associated risks to biota.

The Ivinhema River basin has experienced the greatest expansion of sugarcane cultivation in the state of Mato Grosso do Sul, Brazil. Theassessment of water quality through physical and chemical parameters and ecotoxicological studies, employing both bioindicators collected in situ and laboratory tests, provides more robust results for this region. In this context, the objective of this study was to analyze the composition and structure of the landscape around the sampling sites located in three streams (Vitória, Rosário, and Piravevê) belonging to the Ivinhema River basin to evaluate the impacts of sugarcane cultivation expansion on water quality and genotoxicity biomarkers in situ and ex situ using native fish species. Inthe sampling sites in the Rosário and Vitória streams, sugarcane is the main land use, while in the Piravevê stream, pasture areas represent the main land use. The acidic pH observed in the Vitória and Rosário streams seems to be related to the application of fertilizers and the fertigation in the sugarcane crop. Two species of detritivorous and five of omnivorous fishes were collected. A higher frequency of genotoxic damage was identified in detritivorous fish species. In the genotoxicity tests with Astyanax lacustris, the most frequent nuclear alteration induced by the water samples from all sampling sites was nuclear invagination. Our results indicated that the expansion of the sugarcane ridge in the Ivinhema River basin may cause negative impacts on the aquatic environment and native biota. These results contribute to the generation of data and information that can be used for public hearing requests that aim to discuss and review many aspects of legislation regarding agricultural activities around streams, as well as the need for restoration and management programs in these areas in order to conserve biodiversity.

Abstract Objective In routine clinical laboratories, severe acute respiratory syndrome coronavirus (SARS-CoV-2) infection is determined by reverse-transcription PCR (RT-PCR). In the COVID pandemic, a wide range of antigen detection tests were also in high demand. We investigated the correlation between SARS-CoV-2 NCap antigen and N gene concentration by analyzing samples from several INSTAND external quality assessment (EQA) schemes starting in March 2021. The absolute N gene concentration was measured using reverse transcriptase digital PCR (RT-dPCR) as reference value. Moreover, the performance of five commercial ELISA tests using an EQA inactivated SARS-CoV-2 sample at different concentrations was assessed on the basis of these reference values. Results Quantitative ELISA and RT-dPCR results showed a good correlation between SARS-CoV-2 NCap antigen and RNA concentration, but this correlation varies among SARS-CoV-2 isolates. A direct correlation between SARS-CoV-2 NCap antigen concentration and genome concentration should not be generally assumed. Conclusion Further correlation studies between SARS-CoV-2 RNA and NCap antigen concentrations are needed, particularly in clinical samples and for emerging SARS-CoV-2 variants, to support the monitoring and improvement of antigen testing.

Environmental contamination from mixtures of chemical substances and materials resulting from anthropogenic activities has adverse effects on aquatic biota. Fipronil (FP) is an insecticide widely used in agriculture and public health and is frequently detected in environmental compartments. Microplastics (MPs) represent another class of contaminants that have raised concerns due to their ability to adsorb pollutants, potentially acting as a vector. This study evaluated the influence of polyethylene microplastics on the toxicity of FP in zebrafish (Danio rerio) embryos/larvae. Zebrafish embryos were exposed to aqueous suspension containing purified FP and the FP + MP mixtures for 120 h. Mortality, teratogenicity and cardiotoxicity were observed during the zebrafish development. Larvae were more sensitive to FP than the embryo. The presence of MPs reduced lethality; however, no significant changes were observed for sublethal endpoints. Our findings demonstrate the acute impact of FP on zebrafish embryos/larvae, demonstrating that MPs interfere with toxicity. Therefore, understanding the mechanisms of interaction between contaminants of different classes is essential for predicting the associated risks to biota. [ABSTRACT FROM AUTHOR]

The development of new insecticides for vector control that are toxicologically safe and eco-friendly (such as those obtained from industrial by-products) is an important public health concern. Previous research has shown that the obtained tCNSL (technical cashew nutshell liquid) + NatCNSLS (sodium tCNSL sulfonate mixture) emulsion displayed both surfactant properties and larvicidal activity (LC50-24 h 110.6 mg/L). Thus, the emulsion is considered a promising alternative product for the control of Aedes aegypti. The goal of this study was an ecotoxicological evaluation of the tCNSL + NatCNSLS mixture emulsion and its components. In addition, we compared the toxicity of the tCNSL + NatCNSLS mixture emulsion with toxicity data from larvicide currently recommended by the World Health Organization (WHO). Ecotoxicological tests were performed to assess acute toxicity, phytotoxicity, cytotoxicity, genotoxicity, and mutagenicity using Daphnia similis, Pseudokirchneriella subcapitata, Oreochromis niloticus, Allium cepa, and Salmonella enterica serovar Typhimurium. Regarding acute toxicity, D. similis was the most sensitive test organism for the three evaluated products, followed by P. subcapitata and O. niloticus. The highest acute toxicity product was tCNSL. The tCNSL + NatCNSLS mixture emulsion did not show cytotoxic, genotoxic, or mutagenic effects, and showed low acute toxicity to D. similis. In addition, the tCNSL + NatCNSLS mixture emulsion presented a lower or similar toxicological classification to the larvicides recommended by the WHO. Therefore, ecotoxicological tests suggest that the tCNSL + NatCNSLS mixture emulsion can be considered a larvicide environmentally safe way to control Ae. aegypti.

Ex situ breeding constitutes an important tool for species conservation; however, many reptile species are not managed sustainably under human care due to poor fecundity in ex situ settings. In this study, we tested whether the translocation of a seasonally reproducing species to a different environment results in decoupling of extrinsic signals and intrinsic conditions. The endocrinological patterns of plasma steroid sex hormones, follicular development, and mating behaviour of two female and two male sexually mature Aldabra tortoises (Aldabrachelys gigantea) in a zoological institution in the Northern hemisphere was aligned with enclosure climate data (mean monthly daylight duration, temperature, and precipitation) and compared with respective hormone patterns of wild individuals and climate conditions in the native habitat on the Aldabra Atoll in the Southern hemisphere. Whereas occurrence of mating behaviour was not considered a limiting factor, lack of ovulation and subsequent follicular atresia was the main reason for the lack of reproductive output. While it was impossible to elucidate the triggering factors of ovulation and the multifactorial complexity of reproduction was not fully addressed, this study indicates suboptimal temperature conditions and relative temporal shifts of interacting external triggers (temperature and photoperiod) in the zoo setting. [ABSTRACT FROM AUTHOR]

SARS-CoV-2, the cause of COVID-19, requires reliable diagnostic methods to track the circulation of this virus. Following the development of RT-qPCR methods to meet this diagnostic need in January 2020, it became clear from interlaboratory studies that the reported Ct values obtained for the different laboratories showed high variability. Despite this the Ct values were explored as a quantitative cut off to aid clinical decisions based on viral load. Consequently, there was a need to introduce standards to support estimation of SARS-CoV-2 viral load in diagnostic specimens. In a collaborative study, INSTAND established two reference materials (RMs) containing heat-inactivated SARS-CoV-2 with SARS-CoV-2 RNA loads of ~107 copies/mL (RM 1) and ~106 copies/mL (RM 2), respectively. Quantification was performed by RT-qPCR using synthetic SARS-CoV-2 RNA standards and digital PCR. Between November 2020 and February 2021, German laboratories were invited to use the two RMs to anchor their Ct values measured in routine diagnostic specimens, with the Ct values of the two RMs. A total of 305 laboratories in Germany were supplied with RM 1 and RM 2. The laboratories were requested to report their measured Ct values together with details on the PCR method they used to INSTAND. This resultant 1,109 data sets were differentiated by test system and targeted gene region. Our findings demonstrate that an indispensable prerequisite for linking Ct values to SARS-CoV-2 viral loads is that they are treated as being unique to an individual laboratory. For this reason, clinical guidance based on viral loads should not cite Ct values. The RMs described were a suitable tool to determine the specific laboratory Ct for a given viral load. Furthermore, as Ct values can also vary between runs when using the same instrument, such RMs could be used as run controls to ensure reproducibility of the quantitative measurements.

The symptomatic irreproducibility of data in biomedicine and biotechnology prompts the need for higher order measurements of cells in their native and near-native environments. Such measurements may support the adoption of new technologies as well as the development of research programs across different sectors including healthcare and clinic, environmental control and national security. With an increasing demand for reliable cell-based products and services, cellular metrology is poised to help address current and emerging measurement challenges faced by end-users. However, metrological foundations in cell analysis remain sparse and significant advances are necessary to keep pace with the needs of modern medicine and industry. Herein we discuss a role of metrology in cell and cell-related R&D activities to underpin growing international measurement capabilities. Relevant measurands are outlined and the lack of reference methods and materials, particularly those based on functional cell responses in native environments, is highlighted. The status quo and current challenges in cellular measurements are discussed in the light of metrological traceability in cell analysis and applications (e.g., a functional cell count). An emphasis is made on the consistency of measurement results independent of the analytical platform used, high confidence in data quality vs. quantity, scale of measurements and issues of building infrastructure for end-users.